Wednesday, October 31, 2012

Halloween 2012

The Sky This Week - Thursday November 1 to Thursday November 8

The Last Quarter Moon is Wednesday November 7. Mars enters Ophiuchus and is in binocular distance of some beautiful clusters. Mercury heads into the twilight in the western
evening sky. Jupiter is visible in the late evening sky and is visited
by the Moon on November 1 and 2. In the morning
skies Jupiter and Venus can be readily seen amongst some beautiful
constellations. Total Eclipse on November 14.

Evening sky on Thursday November 2 looking north-west as seen from Adelaide at 5:30 am local daylight saving time in
South Australia. The nearly full
Moon makes a triangle with Jupiter and Aldebaran. Similar views will be
seen elsewhere at the equivalent local time
(click to embiggen).

Jupiter
is easily seen above the north-western horizon in the early morning sky.
Jupiter is below the
Hyades, between the red star Aldebaran and the dimmer blue white star
Elnath. Jupiter moves slowly towards Aldebaran during the week.

Jupiter, Aldebaran and the red star Betelgeuse in Orion form a long triangle
in the sky. With the Pleiades cluster and the constellation of Orion close by, this is a beautiful sight.

Jupiter is now seen in the late evening sky, rising shortly before 11 pm. On the morning of November 2 the nearly full Moonmakes a triangle with Jupiter and Aldebaran.

Bright white Venus is still moderately high above the eastern horizon, but continues sinking lower over the week. Venus looks like a waxing
Moon when seen through even a small telescope.

Venus is in the constellation of Virgo. It approaches the bright star Spica, alpha Virginis, towards the end of the week. Venus
is now relatively low to the horizon, but still clearly visible in
twlight skies. It will become harder to see over the coming weeks. Venus
will still be bright, but hard to see from cluttered horizons.

Evening sky looking west as seen
from Adelaide at 8:30 pm local daylight time on Saturday November 3. Mercury is in the head of the Scorpion. Mars is
high in the body of the Scorpion. Similar views will
be seen
elsewhere at the equivalent local time. Click
to embiggen.

Mercury
is no longer rising in the sky, and is now becoming dimmer. This
will be the
best time to see the swift inner planet in the evening this year. It is
still the brightest object just above the western horizon towards
the end of twilight, just above delta Scorpii in the head of the Scorpion.

Mars enters the constellation Ophiuchus. Mars is
third brightest object in
the western sky (after Mercury and the red star Antares, which is just a
little brighter than Mars). Mars's distinctive red colour makes it
relatively easy
to spot. Mars will be in binocular range of several beautiful clusters for most of the month.

Mars
sets shortly after
11:00 pm local daylight saving time.

Mars
was at opposition on March 4, when it was biggest and brightest as
seen from Earth. Sadly, this is a poor opposition and Mars will be
fairly small in modest telescopes.

There are lots of
interesting things in the sky to view with a telescope.
If you don't have a telescope, now is a
good time to visit one of your local astronomical societies open nights or the local planetariums.

Tuesday, October 30, 2012

Total Eclipse, Australia, 14 November 2012

Morning sky at totality as seen from Cairns on 14 November 2012, 6:38 am (click on image to embiggen)

Morning sky at maximum eclipse as seen from Adelaide on 14 November 2012, 6:48 am (click on image to embiggen)

On November 14 2012, just on Sunrise, there will be a total
eclipse of the Sun visible from Northern Australia. While only a few
places in Northern Australia will see totality, most of Australia will
see a significant partial eclipse, with between 60%-90% of the suns disk
being obscured north of Canberra.

A partial eclipse of the sun is one
that does not cover the whole of the Sun's disk. This is not as
spectacular as a full solar eclipse, but will be incredible in it's own
way. For example, in areas where there is greater than 60% solar disk
coverage, there will be significant darkening and cooling, and the
shadows of leaves will show crescent sun effects. This is also the first
significant solar eclipse in Australia since 2002.

Although T5 is one of my comet "workhorses", its resolution of 1.65 arc-secs/pixel is probably not quite good enough to clearly see the fragment Nick Howes and the and the Remanazacco observatory crew found (blog post here and the discovery images here and a great animation here).

So tonight I snaffled some time on iTelescope T21, with 0.96 arc-secs/pixel I stood a better chance of picking up the fragment, although with the Moon just 30 degrees away, it was a bit of a task.

As with my T5 images from yesterday, I took 20 x 30 second exposures using an R filter and stacked 17 of them (the other 3 were cloud affected) using ImageJ.
I MAXED them then scaled a bit to make the details more obvious. You
will need to click the images to embiggen to see them at full detail.

As well as picking up the tail fragment I saw before, it looks like I have got (poorly) Nick fragment. Compare mine to Nicks image and Rolando Ligustri's image from yesterday using the T11 instrument, which also appears to have captured the fragment.

Saturday, October 27, 2012

Comet 168P Hergenrother has split

Comet 168P Hergenrother has split, the original observation from Nick Howes and the Remanazacco observatory is here (and the discovery images here and a great animation here).

I used iTelescopeT5 to try and take some follow up images, took 20 x 30 second exposures and stacked 17 of them (the other 3 were cloud affected) using ImageJ. I SUMMED them (top left image) or MAXED them (top right image). You will need to click the images to embiggen to see them at full detail.

Well, I found what looks like a fragment (indicated top left), but unfortunately it's not the fragment Nick reported. It looks more like the fragment Robson Hahn reported. Cranking down the image intensity a bit still shows that apparent fragment, and another one closer into the nucleus.

Friday, October 26, 2012

Comet 168P, 23 October 2102

Comet 168P imaged in iTelescopeT5, the image is a stack of 5 x 120 second iages stacked on the comet (that's why the stars are elongated) . Image stretched in FITS liberator, then SUMMED in ImageJ and despeckled (click to embiggen).

Comet 168P Hergenrother continues to be bright, and there have been suggestions that there are fragments in the coma of the comet, but my image isn't high resolution enough to show that.

Tuesday, October 23, 2012

The Sky This Week - Thursday October 25 to Thursday November 1

The Full Moon is Tuesday October 30. Mars climbs the scorpion and comes close to some beautiful clusters. Mercury rises higher in the western
evening sky. Jupiter is visible in the late evening sky and is visited by the Moon on November 1. In the morning
skies Jupiter and Venus can be readily seen amongst some beautiful
constellations.

Evening sky on Thursday November 1 looking west as seen from Adelaide at 11:30 pm local daylight saving time in
South Australia. The nearly full Moon makes a triangle with Jupiter and Aldebaran. Similar views will be seen elsewhere at the equivalent local time
(click to embiggen).

The Full Moon is Tuesday October 30.

Jupiter
is easily seen above the northern horizon in the early morning sky.
Jupiter is below the
Hyades, between the red star Aldebaran and the dimmer blue white star
Elnath. Jupiter stays in roughly the same position for most of the week.

Jupiter, Aldebaran and the red star Betelgeuse in Orion form a long triangle
in the sky. With the Pleiades cluster and the constellation of Orion close by, this is a beautiful sight.

Jupiter is now seen in the late evening sky, rising shortly before 11 pm. On the evening of November 1 the nearly full Moon makes a triangle with Jupiter and Aldebaran.

On the 28th-29th, starting at 23:20 am AEDST, there is a nice series of
transits and shadow transits of Jupiters Moon Io.

Bright white Venus is still moderately high above the eastern horizon, but continues sinking lower over the week. Venus looks like a waxing
Moon when seen through even a small telescope.

Venus is in the constellation of Virgo. On the 26th and 27th it is close to beta Virginis. Venus
is now relatively low to the horizon, but still clearly visible in
twlight skies. It will become harder to see over the coming weeks. Venus
will still be bright, but hard to see from cluttered horizons.

Evening sky looking west as seen
from Adelaide at 8:30 pm local daylight time on Thursday November 1. Mercury is in the head of the scorpion. Mars is high in the body of the Scorpion. Similar views will
be seen
elsewhere at the equivalent local time. Click
to embiggen.

Mercury
is still rapidly rising in the sky, but is now becoming dimmer. This will be the
best time to see the swift inner planet in the evening this year. It is still the brightest object just above the western horizon towards
the end of twilight.

Over the week Mercury rises towards the head of the Scorpion. By November 1 it will be in the head of the Scorpion near delta Scorpii.

Mars
continues to move through Scorpius. Mars is
third brightest object in
the western sky (after Mercury and the red star Antares, which is just a
little brighter than Mars). Mars's distinctive red colour makes it
relatively easy
to spot. From around the 27th Mars will be in binocular range of several beautiful clusters.

Mars
sets shortly after
11:00 pm local daylight saving timetime.

Mars
was at opposition on March 4, when it was biggest and brightest as
seen from Earth. Sadly, this is a poor opposition and Mars will be
fairly small in modest telescopes.

There are lots of
interesting things in the sky to view with a telescope.
If you don't have a telescope, now is a
good time to visit one of your local astronomical societies open nights or the local planetariums.

Monday, October 22, 2012

The Rivals

Mars near the red star Antares on Monday October 22, 2012. Mars is the bright object to the right of centre, 2/3rds of the way down, Antares is the bright object near centre. Mercury is the bright object just above the roofs (click to embiggen).

Close-up of Mars near Antares.

As you know, the name Antares means "Rival of Mars". Both objects are red, and for a good part of the year they are of similar brightness. Of course one is a red giant star, the other a modest sized planet. Ironically, Antares is so big that Mar's orbit would lie inside the rival star.

Tonight they looked good together, giving the Scorpion a very unusual shape.

Thursday, October 18, 2012

Alpha Centauri B has a (red hot) Earth-sized Planet

Australian's can never look at the sky the same way again. When you go out tonight to look at the southern sky, you know that alpha Centauri, the red star in the iconic pointers, the pair of stars that point to the Southern Cross, has an Earth-sized world orbiting it.

A hellish, red hot world, true. One that screams around it's sun (alpha Centauri B, alpha Centauri is a triple star system) in just over 3 days. It snuggles closer to its sun than Mercury does to ours and its surface is most likely covered in a magma ocean. Not the place that bright eyed pioneers would fly to in gleaming silver spaceships.

But its a world around one of the southern hemisphere's iconic and brightest stars. Sure we have something like 800+ confirmed planets around other stars, a fair few solar systems, and even one or two have planets in the hypothetical habitable zones of their suns.

But the vast majority are too dim to see with the unaided eye, or barely visible, and rejoice in names like GJ 1214b, Gleise 581 e, Upsilon Andromedae A and 55 Cancerii e.

Alpha Centauri Bb, simulated in Celestia with two of its three suns visible.

In contrast alpha Centauri is bright, and part of an easily recognisable asterism. It looms large not only in the skies of the southern hemisphere, but also our fiction and imaginations.

In terms of our stepping stones into space, The Moon, Mars* and then alpha Centauri, the triple star system on our doorstep a little over 4 light years away, has loomed large. Alpha Centauri has featured heavily in science fiction too, and Pandora, the world of the Na'vi, orbits Alpha Centauri A. The new world orbits alpha Centauri B as mentioned above.

Could there be other planets in the alpha Centauri system, ones that are more like our familiar planets?

Certainly, although they may be hard to find. This new world (we have to think of a name for it, Mustafar is already taken, how about magmamare) was discovered by the slight doppler shift in its stars light as the planet tugged on its sun as it orbited.

This means in these kinds of searches its easier to find big things close to their suns (which explains why until recently most of the extrasolar planets we found were massive things bigger than Jupiter as close or closer than Mercury). To find a Jupiter- like world in a Jupiter like orbit, we would have to watch the system for 36 years (as we need to watch 3 orbits to make sure the signal is real).

So there's a real chance that there are other, more familiar worlds circling the alpha Centauri system, and you can bet people will be looking for them now.

Next time you go outside and look south at the pointers, you will now know that there is a world, out there, not of our solar system, that is tantalisingly just beyond our reach.

Once again I've made Celestia files for the system. As
usual, copy the data here to plain text files (alphacentBb.ssc) and copy the file to the Celestia extras folder.
=====================8<=cut===================================
"b" "Rigel Kentaurus B"

# Earth like world around alpha centauri B
# Found by ESO HARP instrument

{
Texture "venussurface.*"
# Using venus although it may be a magma world

}
=====================8<=cut===================================
*Venus, despite looking like Earth's twin, never seems to garner quite the same attention, perhaps because Mars is in the direction of out.

Tuesday, October 16, 2012

The Sky This Week - Thursday October 18 to Thursday October 25

The First Quarter Moon is Monday October 22. Mars comes close to the bright red
star Antares in the Scorpion on the 22nd as well. Mercury rises higher in the western
evening sky. The thin crescent Moon is near Mars
on the 18th. Jupiter is visible in the late evening sky. In the morning
skies Jupiter and Venus can be readily seen amongst some beautiful
constellations. The Orionid meteor shower is best seen on the morning of the 22nd.

Morning sky on Monday October 22 looking
north-east as seen from Adelaide at 3:00 am local daylight saving time in
South Australia. The cross marks the position o the Orionid radiant.
Similar views will be seen elsewhere at the equivalent local time
(click to embiggen).

The First Quarter Moon is Monday October 22.

Jupiter
is easily seen above the northern horizon in the early morning sky.
Jupiter is below the
Hyades, between the red star Aldebaran and the dimmer blue white star
Elnath. Jupiter stays in roughly the same position for most of the week.

Jupiter is now seen in the late evening sky, rising shortly before midnight.

On the 20th, starting at 2:58 am AEDST, there is a nice series of
transits and shadow transits of Jupiters Moons, with the great red spot
in sight.

Jupiter, Aldebaran and the red star Betelgeuse in Orion form a long triangle
in the sky. With the Pleiades cluster and the constellation of Orion close by, this is a beautiful morning sight.

Bright white Venus is still moderately high above the eastern horizon, but continues sinking lower over the week. Venus looks like a waxing
Moon when seen through even a small telescope.

Venus starts the week in the constellation of Leo, but finsishes it in the constellation of Virgo. Venus
is now relatively low to the horizon, but still clearly visible in
twlight skies, but will become harder to see over the coming weeks. It
will still be bright, but hard to see from cluttered horizons.

The Orionid Meteor shower peaks on the morning of October 22 in Australia, the radiant for the Orionids
rises around 1 am on October 23, with the best meteor viewing being
between 3:00 am and 4:00 am. You can expect to see roughly a meteor
every 5 minutes or so under dark skies.

As the name suggest, the
meteors will seem to originate just below Orion. Allow several minutes
for your eyes to adjust to the darkness and be patent, it may take ages
for a meteor to turn up, then you may see a few in a row.

You can use the Meteor Flux Estimator
to predict the number of meteors you might see at your location. Choose
8 Orionids, and make sure the date is 2011 and you have DST on if you
are in daylight saving zones.

Evening sky looking west as seen
from Adelaide at 8:30 pm local daylight time on
Wednesday October 18. Mars is in the head of the scorpion, coming close
to Antare sand the crescent Moon. Mercury is below. Similar views will
be seen
elsewhere at the equivalent local time. Click
to embiggen.

Mercury
is rapidly brightening and rapidly rising in the sky. This will be the
best time to see the swift inner planet in the evening this year. It is
currently the brightest object just above the western horizon towards
the end of twilight.

Over the week Mercury rises towards the head of the Scorpion..

Mars
continues to move through Scorpius. Mars is
third brightest object in
the western sky (after Mercury and the red star Antares, which is just a
little brighter than Mars). Mars's distinctive red colour makes it
relatively easy
to spot, just don't confuse it with red Antares above it. On the 22nd Mars is at it's closest to Antares.

Mars
sets shortly after
11:00 pm local daylight saving timetime.

Mars
was at opposition on March 4, when it was biggest and brightest as
seen from Earth. Sadly, this is a poor opposition and Mars will be
fairly small in modest telescopes.

There are lots of
interesting things in the sky to view with a telescope.
If you don't have a telescope, now is a
good time to visit one of your local astronomical societies open nights or the local planetariums.

The Crescent Moon near Mercury and Mars (17-18 October, 2012)

Western evening sky at 8:30 pm ACDST 17 October as seen from Adelaide. Similar views will be seen elsewhere at equivalent local time (click to embiggen).

Western evening sky at 8:30 pm ACDST 18 October as seen from Adelaide. Similar views will be seen elsewhere at equivalent local time.

The next few nights are an excellent time to view fleet Mercury, especially on the 17th (Wednesday night) when the crescent Moon is close to Mercury. Once you know where Mercury is keeping an eye on it over the coming nights as it heads towards the Scorpion is a breeze.

On the 18th, The crescent Moon is close to Mars, as it heads for its doppelgänger Antares.

Guess What Arrived in the Post Today?

My complementary copy of "Best Australian Science Writing 2012" arrived today. I'm one of the writers included in the anthology (see..that's my name on the cover, along with some Australian greats like Margaret Wertheim .. [/Waynes World]I'm not worthy[/Waynes World]).

It's a really good read, showcasing some great science writing from Australians (the mediation on the media and the diamond planet is great!). If you want to but a copy over the internet see here.

Monday, October 15, 2012

Comet 260P McNaught Amongst the Galaxies (7 and 8 October 2012)

260P on 7 October, stack of 5 x 120 second images from iTelescopeT5. The thin spindle shaped galaxy is UGC 1500, the large spiral is NGC 753. Click to embiggen

260P on 8 October, stack of 3 x 120 second images from iTelescope T5. The thin spindle shaped galaxy near the bottom is UGC 1500 again, there's a lot of smaller galaxies, including UGC 1366 not far from the comet. Click to embiggen

Comet 186P Hergenrother and lots of teeny tiny galaxies

Comet 168P Hergenrother is a rather nice little comet that surprised everyone by going into outburst. After reaching magnitude 9 (when it was supposed be be no brighter than magnitude 15), it has begun to fade.

However, it is still quite bright, around magnitude 10.

After missing out on imaging the comet (weather, asteroid 2012 TC4, other distract.. Ohhhh Shiny), I finally got a nice image of it. If you embiggen the image, you will see lots and lots of teeny tiny galaxies.

On the 14th and 15th 168P is in T5 distance of some nice galaxies, 14.7 magnitude UGC 12803 on the 14th and 12.2 magnitude NGC 7753 on the 15th. Well worth going after.

Mars in the Head of the Scorpion (11-13 October)

11-10-12 (click to embiggen) 15 second exposure, ASA 400, Canon IXUS

12-10-12

13-10-12

11-10-12 close up (click to embiggen) as above but 3x zoom

12-10-12

13-10-12

While asteroid 2012 TC4 has been taking up a lot of my time, other things have been happening in the sky. Mars entered the head of Scorpius the Scorpion, and is rapidly climbing the asterism towards the red star Antares the "Rival of Mars".

This is a series of images I took from 11 October - 13 October. Mars is the object that is obviously moving from frame to frame.

Sadly, cloud has covered tonight's view (and covered Venus being close to the crescent Moon). If you embiggen the large scale view from 12 October (middle top), you can see Mercury right down the bottom.

Near Earth Object 2012 TC4 Flys by (12 October 2012)

Images taken form 2:00 UT on, when the 22 meter asteroid was just 5 hours from closest approach of a mere 0.2 Earth Moon distances away. Not satellite scraping, but still reasonably close.

Overlay of all 5 images using the MAX Z project function of ImageJ
(click to embiggen for full asteroidal awesomeness). Images were processed with fairly strong adjustment to brightness and contrast.

There is a very large difference in the brightness of the asteroid in these images (look carefully for the first one, it zips through the bright star image). This implies the asteroid is rapidly rotating and of uneven shape or colour.

Sadly at closest approach it was below the horizon from all of the iTelescope scopes.. But I was able to catch it just on astronomical twilight.

Chart of the area around asteroid 2012 TC4. The rectangle is the field of view of iTelescope T5. The circles are the MPC ephemeris positions for 2012 TC4, corrected for parallax as seen from Mayhill New Mexico. The Skymap generated positions from the MPC ephemeris are not anywhere near the parallax corrected positions (click to embiggen).

Unlike yesterday, when the asteroid was moving fast, but not too fast, today as 2012 TC4 was coming within 0.2 Earth-Moon distances of us, it was moving at a fair clip of around 10 arc seconds per minute at the time of imaging.

Under these circumstances trying to track the asteroid with one-line elements would fail (the scopes drives can't push it that fast).

So I used my standard technique, which is to choose a star not far from where the asteroid would be, and set that as the target, then wait for the asteroid to zoom by. "Would be" was the operative word. The asteroid was moving so fast that by the time the telescope slewed to the position were the asteroid was, it would have moved out of frame.

So I measured the time T5 took to slew, autofocus and begin imaging in a series of recent images, and used the average time from start of my run to actual imaging (around 5 minutes) to set the telescope position.

I started the run exactly at astronomical twilight (1:55 UT), and set up the image area to cover where the asteroid would be 5 minutes later. And lo and behold it worked!

Here's a video of the pass. I would have gotten more images but some git was hogging the scope fro something called the Pluto Project (Oh wait! That's me!)

Southern Skywatch October 2012 Edition is now up.

Evening sky looking west as seen from Adelaide at 8:30 pm local daylight time on Wednesday October 17. Mars is in the head of the scorpion, coming close to Antares. Mercury is close to the crescent Moon. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.

The October edition of Southern Skywatch is now up. Late sadly, but lots of family stuff and being away from the computer is respobsible for it.

There's still lots of planetary action this month.

Venus is low in the morning sky
and is close to the crescent Moon on
the 13th.

Jupiter is in the morning sky near the Hyades, on the 6th the crescent Moon
and Jupiter were close with an occultation.

Mars is in the head of the Scorpion. Mars is close to the crescent
Moon on the 18th.

Mercury is at its best this month, and is close to the crescent Moon on the 17th.

Near Earth Asteroid 2012 TC4 11 October 2012

Near Earth Asteroid 2012 TC4 imaged with iTelescope T14 (New Mexico) on 11 October 2012. The image is a stack of 5 x 120 second exposures. The images were stretched in FITSLiberator, then stacked in ImageJ, a MAX Z project made and a light despeckle.

By Touatis, 2012 TC4 is giving me grief! More than almost any other NEO I've tried to image. My attempts to capture it in iTelescope T5 using the MPC 1 line ephemeris with tracking has come to naught, even stacking 10 x 90 sec images did not reveal the 22 meter asteroid.

iTelescope T14 was more accommodating, and I was able to capture the little blighter. Mind you, it required a lot of hunting about in the image to find it. The asteroid was magnitude 15.9 when the image was taken. It is at closest approach on the 12th at 6:35 UT, but that will be below the horizon of the northern hemisphere iTelescope scopes.

Even so, just before closest approach, the asteroid is moving at such a spanking pace (I don't thing the auto-guide can push the scopes to follow the asteroid it is going so fast) it will be a challenge to image, and so close to earth that standard planetarium programs will have not plot it correctly.
My guide to imaging 2012 TC4 is here.

Tuesday, October 09, 2012

The Sky This Week - Thursday October 11 to Thursday October 18

The New Moon is Monday October 15. Mars comes close to the bright red star Antares in the Scorpion. Mercury rises higher in the western evening sky. The thin crescent Moon visits Mercury on the 17th, and Mars on the 18th. Jupiter is visible in the late evening sky. In the morning skies Jupiter and Venus can be readily seen amongst some beautiful constellations. On the morning of the 13th the thin crescent Moon is near Venus.

Morning sky on Saturday October 13 looking east as seen from Adelaide at 5:30 am local daylight saving time in South Australia. The crescent Moon is above Venus.
Similar views will be seen elsewhere at the equivalent local time
(click to embiggen).

The New Moon is Monday October 15.

Jupiter is easily seen above the norther horizon in the early morning sky. Jupiter is below the
Hyades, between the red star Aldebaran and the dimmer blue white star Elnath. Jupiter stays in roughly the same position for most of the week.

On the 13th, starting at 1:04 am AEDST, there is a nice series of transits and shadow transits of Jupiters Moons, with the great red spot in sight.

Jupiter, Aldebaran and the red star Betelgeuse in Orion form a long triangle
in the sky. With the Pleiades cluster and the constellation of Orion close by, this is a beautiful morning sight.

Bright white Venus is still moderately high above the eastern horizon, but continues sinking lower over the week. Venus looks like a waxing
Moon when seen through even a small telescope.

Venus is in the constellation of Leo, not far from the bright star Regulus. Venus moves further away away over the rest of the week. Venus is now relativey low to the horiozn, it is still clearly visible in twlight skies, but will become harder to see over the coming weeks. It will still be bright, but hard to see from cluttered horizons.

On the morning of the 13th the thin crescent Moon is near Venus. This is also an excellent opportunity to see Venus in the daylight.

Evening sky looking west as seen
from Adelaide at 8:30 pm local daylight time on Wednesday October 17. Mars is in the head of the scorpion, coming close to Antares. Mercury is close to the crescent Moon. Similar views will be seen
elsewhere at the equivalent local time. Click
to embiggen.

Mercury
is rapidly brightening and rapidly rising in the sky. This will be the best time to see the swift inner planet in the evening this year. It is currently the brightest object just above the western horizon towards the end of twilight.

On the 17th Mercury is close to the thin crescent Moon.

Mars continues to move through Scorpius. Mars is
third brightest object in
the western sky (after Mercury and the red star Antares, which is just a little brighter than Mars). Mars's distinctive red colour makes it
relatively easy
to spot, just don't confuse it with red Antares above it. Mars sets shortly after
11:00 pm local daylight saving timetime.

Mars
was at opposition on March 4, when it was biggest and brightest as
seen from Earth. Sadly, this is a poor opposition and Mars will be
fairly small in modest telescopes.

Mars starts the week in the head of Scorpius the
Scorpion. On the 11th it is close
to the bright star delta Scorpii. Over the week Mars comes closer to the bright red star Antares (whose name means "rival of Mars"). On the 18th the crecent Moon forms a line with Mars and Antares.

There are lots of
interesting things in the sky to view with a telescope.
If you don't have a telescope, now is a
good time to visit one of your local astronomical societies open nights or the local planetariums.

Monday, October 08, 2012

Aurora Happening Now in Tasmania

Aurora are being seen in Tasmania NOW (Monday 8 Oct 9:14 pm) despite heavy
cloud. Kp is only 4, but Bz is -10 nT or so. Go out and have a look if you are
in Tassie, New Zealand and possibly Southern Victoria. Look to the south.

My Images of the Jupiter-Moon Graze, October 6, 2012

Jupiter and Moon at 5:37 am ACST, October 6. A brief thinning of clouds allows Jupiter to be seen.

6:30 am, first usable shots through the telescope with the Canon IXUS (400 ASA automatic exposure length) using 20 mm Plossl lens. Jupiter is the pale blob near the top (remember the telescope inverts the image from what you see with the unaided eye, which is why Jupiter is on a different side to the camera image on the left)

6:34 am

6:44 am, Jupiter is clearly moving closer to the Moon.

6:51 am, Switch to 12 mm Plossl Lens. Black dots and such are rubbish on the CCD chip.

6:58 am, despite a big gap in the clouds, seeing is degenerating rapidly.

7:07 am, gaps in cloud fewer and further between

7:17 am, thin cloud making things difficult.

7:20 am, almost at graze, very poor seeing

7:26 am, last "usable" shot before clouds move in completely. Barely visible Jupiter is just touching the Moon.

I love occultations, but I like grazes better, where the planet just skims over (or is only partly hidden by) the Moon better, as these are more dramatic.

Today's graze broke a long drought in bright planet occultations for me. Okay, it was during daylight, which is not so good for observation or photography as both the Moon and Jupiter are very washed out, but seeing a planet move behind the Moon in daylight is pretty cool too.

Of course it was cloudy (see my semi-live blog here), but I set up just in case there were holes in the cloud coming through. And I was rewarded with sufficient gaps to take some half-way (but only half-way) decent shots.

I used my little 4" scope, as I could rapidly move it out of the way if the cloud turned to rain (unlike the 8", which is a pain to move and have to be partly disassembled). I also used the through lens camera adapter and my Canon IXUS digital camera rather than the webcam and laptop combination for the same reason (and the laptop screen is difficult to read in daylight).

This reduced the image quality I could get a bit (especially as the IXUS CCD chip has started accumulating rubbish on it) but gave me better flexibility. I started off shooting through a 20 mm Plosssl lens, then swapped to a higher magnification 12 mm Lens when Jupiter got close. Give the poor seeing from atmospheric turbulence and the persistent cloud, this was probably a mistake. Although the images were bigger, the planet and lunar brightness was better in the 20 mm.

I did a telephone interview with Ashley Walsh on 891 ABC radio, sadly the clouds were fully over at that time so I couldn't describe the telescope view for the listeners, but hopefully it inspired a few people to look. I was going to mention the scientific benefits of occulations, but got a bit carried away descibing what I hoped people would see and emphasising safety for daylight telescope use,

I did also check the view with binoculars, while I couldn't see Jupiter with the unaided eye (probably too much cloud), it was very clear near the Moon with binoculars.

Sadly, just as the most interesting part of the occutlation turned up, the actual graze itself, thick clouds with absolutely no breaks in them came over and lurked heavily. I packed up then.

Nonetheless, despite the cloud hi-jinks and relatively poor seeing, it was a pretty fascinating and beautiful even, well worth getting up for and persisting with.